burlingham



W. BURLINGHAIVI. PNEUMATIC IMPACT TOOL. APPLICATION man AUG. l, 1 914.

Patented June 10, 1919.

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. ATTORNEYS 'W. BURLINGHAM.

PNEUMATIC IMPACT TOOL. APPLlc'ATIoN FILED Aue. l. |914.

l SAOELSG i Patented June 10, 1919..

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Ar-TABENEYS 'wf BURUNGHAM.

PNEUMATIC IMPACT ooL. I APPLICATION FILED AUGI| 15H4. 1,306,530@Patented June 10, 1919.

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` ATTURNEYS W. BURLINGHAM. PNEUMAHC lMPAcT T ooL. APPLRCATION FILED AUG.I,1914. 1936,0@9 I Patented June 10, 1919.

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WITNESSES ATTORNEYS MESNE ASSIGNMENTS, T0 ENGINEERING PRODUCTS NEWS,VIRGINIA, -A CORPORATION 0F VIRGINIA.

IPNEUMATIC IMPACT-TOOL.

Specification of Letters Patent.

Pwtenteol J une 10), 1919.

Application filed August 1, 1914. Serial No. 854,478.

To all whom t may concern:

Be it known that I, WILLIAM BURLING- HAIna `citizen of the/UnitedStates, residing aft Newport News, county of Warwick, Stateof Virginia,have invented a new and useful Pneumatic Impact-Tool, of which thefollowing is a specification. l

In large industrial plants, such as shipyards, boiler-works, stonedressing plants and the like, where large numbers of pneumatic hammersfor riveting, chipping, calking and kindred uses are constantlyemployed, the problem of economically furnishing, keeping up orincreasing the compressed air equipment for the operation of said toolshas become an important economical item in shop management, and theprimary object, therefore, of my invention is to provide a novelconstruction of pneumatic hammer, having a novel fluid distributionsystem therein, whereby the cost of .maintenance of the compressed airequip-A ment is greatly reduced, and wherein the greatest possibleeil'iciency can be attained with the greatest economy inthe volume ofthe motive fiuid consumed. Formerly, when comparatively few pneumaticimplements were used inlarge plants, as even now in smallerestablishments where 'but a small number of such tools are used, thequestion of the quantity of the cubic volume of air used was given butlittle consideration, as

an air compressing plant supplying a suiicient amount of air under agiven pressure could usually be erected at a-reasonable out-` lay, andwithout occupying an excessive area. Usually, the quantity of airconsumed by the pneumatic hammering tools was more or less ignored, solong as the results in power of the tools was attained.

At the present time, however, in large in- `dustrial plants, wherepneumatic tools and other pneumatic appliances are extensively used, thesize and initial expense of the' air compressors and the space occupiedby them, as well as the power and ,fuel required for their dailyoperation and the incident costof their i istallation, operation andmaintenance, have assumed proportions of such magnitude as to requirecareful attention, and have become of 'sufficient impartance to requirethe careful consideration of remedies to reduce unnecessary expense inthis connection, and it is with the object of obtaining much greatereiciency from a given volume of air at a given pressure, `as well asgreater power, in a pneumatic impact tool for riveting, chipping oranalagous uses, that my novel tool is designed.

In its broad aspects, my present invention conslsts 1n the employment ofcertain of the broad generic features of my Patent No.. 1,123,678,granted 'January 5th, 1915, to which I have added in the present case,novel means for enabling the hammering ypiston or plunger to beoperatedon its downward or outward stroke by the direct action upon bothits piston areas of live air, the

CORPQRATION, NEWPORT control of the distribution system of said -liveair or other motive fluid being effected by a novel valve mechanism tobe hereinafter referred to.

Y My invention further consists of a novel construction of pneumaticimpact tool provided with means for adapting such tool to either operateon the compound principle, utilizing air which'has acted against asmall-area piston to act upon another piston, or to operate by thedirect action upon both pistons of the normal pressure live air. 4Itfurther consists of such a tool in which the return or lip-stroke of thepiston is actuated by the differential expansion action of the air whichhas driven the pistons down .upon the differential area pistons. l

It further consists of such a tool in which the longitudinalair-distributing channels are formed by grooves ,in the surfaces oftelescoped or interfitted cylindrical parts of the working barrel,whereby drilling of such channels and plugging of the ends of drilledholes'is avoided.

It further consists of means in such a hammer for cushioning the recoilof by a permanent air-cushion.

It further consists of other novel features of construction, all as willbe hereinafter fully set forth. L

For the purpose of illustrating my in.-v vention, I have shown in theaccompanying drawings, one form thereof which is at present preferred byme, since the same will give in practice satisfactory and reliableresults, although it is to be understood the tool l that the variousinstrumentalities of which 45 lower end of the working cylinderillustratmy invention consists can be variously arranged and organizedand that my inven.

tion is not limited to the precise arrangement and organization of theseinstrumentalities as herein shown and described.

In said annexed drawings- Figure 1 represents an axial or longitudinalsection of a pneumatic hammer embodying my invention.

Fig. 2 represents a diagrammatical view of the hammer illustrating thearrangement and connections of the cylinders, plunger, valves andconduits of the tool, the plunger being illustrated atthe extreme of itsupstrOke.

Fig. 3 represents a similar diagram with the plunger at the extreme ofits downstroke.

Fig. 4 represents a transverse section' on the line win Fig. 1.

Fig. 5 represents a transverse sectionl on the line y-g/ in Fig. 1, withthe barrel-block removed.

Fig. 6 represents a transverse section on the line a-z in Fig. 1.

Fig. 7 represents a transverse section on the l1ne w-w in Fig. 1.

Fig. 8 represents a detail view, partly in section and broken away, ofthe upper portion of the hammer barrel.

Fig. 9 representsan end-view of the cylinder jacket or casing.

Fig. '10' represents a section of as much of the barrel as willillustrate the channel inthe same for the tool cushioning device.

Fig. v11 represents'an axial section of the barrel illustrating thechannel conveying air to the lower end of the plunger cylinder.

Fig. 12 represents a sectional detail view of as much of the workingbarrel as will illustrate the channel for conveying air from thesmall-diameter cylinder to the receiver.

'Fig. 13 represents an axial section of the ingv a form of cushionmgdevice -for the l working tool.

Similar numerals of reference l indicate corresponding parts in thefigures. u

Referring to` the drawings, 1 deslgnates a 'cylinder-jacket or casing,formed with a large-diameter axial bore, 2, in its upperA portion, andan axial bore, 3, of smaller diameter having an inwardly projectingannular flange, 4, at its lower end. A split tool-socket, 5, having areduced end, 6, at its end, fits in thel lower end of the smaller bore:of the jacket with such reducedendproj ecting through the vflangedopening and the 'shoulder of such reduced end bearing against lsaid ange4. A lining-sleeve, 7, lits inthe small diameter bore thereby. formingthe larger or low p ressure cylinder and has its lower end bearlng in anannular rabbet, 8,

ing the high pressure cylinder, as stated.

A handle, 11, formed with an inlet passage, 12, to which the motiv-fluid'supply can be connected, and contro ed by a throttle-valve, 13,has a longitudinally slit socket, 14, into which the upper end of thecylindersaid jacket by a nutted clamping bolt, 15, passing throughperforated ears, 16, at the jacket fits and which can be clamped upon`sides of the slit in the socket. The jacket has preferably two-diametrically opposite pairs of threads or peripheral flanges, 17,

which can enter longitudinal recesses, 18, in the socket and by turninglthe socket and jacket, one in its relation to the other, can engagegrooves, 19, in the interior of the socket, by meansl of whichprovisions the jacket and socket are locked against longitudinalmovement.`

vThe split tool-socketis formed near the upper end of its bore with anannular recess, 20, which communicates by oblique holes, 21, with anexternal peripheral groove, 22, into which opens an air passage formedby a longitudinal groove, 23, in the small-diameter bore of the jacketand the lining-sleeve communicating with a longitudinal groove, 24, inthe barrel-block and connected to a passage, 25, permanentlycommunicating with the live-air supply, by means of Which a constant airsupply is provided to form an air-cushion in the annular recess in thetoolsocket. A sleeve, 26, having an annular piston-flange, 27, isslidable in the upper end of the tool-socket with its piston-flangewithin the recess, and the shank, 28, of the working tool, which may bea rivet-set, a chisel, a calking-tool or any other form vof tool, asrequired, is formed with a reduced. inner end, 29, fitting in the sleeveand has its shoulder bearing against the end of the sleeve, so that therebound of the tool will act through the flange of the sleeve againstthe air-cushion in the recess of tl}e, tool socket and the recoil -willthus be cushioned barrel-block and lining-sleeve, and consistsA of acylindrical piston, 31, fitting to slide in the smaller f diameter boreof the barrel- -block, and a short piston, 32, at the lower end of saidlong piston and fitted to slide in the larger diameter bore of theliningsleeve. The lower Aface of the large piston has ,a strikingprojection, 33, which in the operation of the tool strikes the inner endof the tool-shank. The long differential piston 30 is preferably hollowas indicated at 34, throughout its length, which serves to decrease theweight of the plunger. Periph- Fig. 4, the valve-chamber 37 has alarger,

'diameter bore, 39, and a smaller diameter bore, 40, and a spool-valvehaving t-wo larger-diameter valve-disks, 41 and 42, and two smallerdia1neter.valve-disks, 43 andv I 44, is movable in said valve-chamber.'The larger diameter bore has a port, 45, which communicates with theupper end of the upper smaller-diameter bore of the plungercylinder by apassage, 46,. and an inlet-port, 47, communicating with the live-airsupply by a passage, 48, vto have the valvedisks 41 and 42 connect saidports when the valve is in its upper position. rlhe upper end of thevalve-chamber communicates by a passage, 49, with the smaller-diameterbore of the plunger-cylinder through a port, 50, in the same and at adistance from the upper end to be uncovered by the piston when the sameapproaches about one-half of its down-stroke. A port, 51,at the lowerend ofthe large-diameter valve-chamber is in constant communication withthe live-air supply through a passage, 52. ."The small- K diametervalve-chamber has, a port, 53,com-

municating with lthe upper end of the larger-diameter bore of theplunger cylinder by a passage, 54, and said valve-chamber has a port,55, adjacentsaid former port` to be connected with the same by theSpacebetween the small-diameter valve-disks when the. valve is movedupward, and connected to anl air-receiver, 56, by a passage, 57 Saidreceiver is preferably formed between the side of the large bore in thecylinder-jacket and a' longitudinal recess, 58, inthe side of' thebarrel-block A port, 59,'is formed at the lower end-ofthefsm'all-diameter valve f chamber and communicatesf'with t e live'-`when the latter is at the lower end 'of its' 'air inlet by, a passage,60, controlledby a valve-plug, 61, andwith a port, 62,'-i'n` thesmall-diameter plunger-bore which` w` i ll be uncovered, by the smallpiston of Vthe 'saine down-stroke, by passage, 63, controlled Thevalve-chamber 3 8 alarga-diameter f chamber, 65, and a small-diameterchamber 66, and a valve having two large-diameter pistons, 67 and 68,and two small-diameter pistons, 69 and 70, is slidable in saidvalvechamber. The upper end of the valvechamberhas a passage, 71,opening from it and having a branch-passage, 72, opening through a port,73, in the small-diameter cylinder-bore at a point near the lower end ofthe same to reglster with the upper annular groove 36 in thesmall-diameter piston when the latter is at the lower extreme of itsstroke. A port, 74, registers with said former port and communicateswith the receiver through a passage, 75. The passage from the upper endof the .last-described valve-chamber also communicates through apassage, 76, and port, '77, with the lower end of thesmall diameterpiston-bore, at a point where it will register with the lowerannulargroove 35 in the small-diameter piston when the latter is at theextreme of its up-stroke. A port, 78, in the bore registers with saidfirst-mentioned port and communicates with the atmosphere through apassage, 79, and another port, 80, in the bore registers with said twoports and communicates through a branch-passage, 81, with the passage 49from the upper end of the first described valve-chamber, so that theupper ends of the two valve-chambers can be simultaneously put inexhaust-com munication with the atmosphere when the plunger arrives atthe extreme of its' upstr'oke. A. port, 82, near the upper end of thelarge-diameter valve-chamber communicates with the atmosphere through"an eX- haust-passage, 83. A port, 84, in the largediameter valve-chamberis connected by a passage, 85, to the lower end of the largediameterpiston-bore, and the longitudinal portion of said passageI is formed bya groove, 86 in the small interior bore of the v valve-disks vat themiddle of the valve. An

annular port, 93, is formed in the -small diameter .l valve-chamber andcommunicates by "a passage',`94, 'with the upper end of thelarge-'diameter piston-chamber, and an annu1a'r`port,95,lin the lowerportion of the small-diameter -valve-chamber has perma- -nentcommunication with the atmosphere by av passage, 96. The form ofcushioning device for the working-tool illustrated in Fig. 13 is inseveral respects preferable to. the form for-- merly described andillustrated. A sleeve, 100, is secured in the lower end of the barrel,bearing against the flange 4 of the latter, and said sleeve is held inplace by the lining sleeve 7 and has an enlarged recess portion, 101, inits bore, the upper end of which communicates through oblique holes,102, with an annular groove, 103, in the sleeve which receives livemotive fluid through the channel 23, in the same manner as the annnulargroove heretofore described. A tool-socket,

A 104, within whichthe shank 28 of the working tool lits, fits to slidein the sleeve and has an annular piston, 105, which is slidable in theenlarged lrecess of the sleeve, and, liveair continually being admittedthrough the groove and oblique holes into the recess back of the annularpiston, the recoil of the rebounding tool will be largely absorbed bythe air-cushion thus produced The sleeve .v and tool-socket can beeasily slipped from above into the cylinder and held in place by thelining sleeve andthe other elements above the same. 4 l

The present form of pneumatic hammer is constructed in such a mannerthat it can either be operated by liv -air acting against the face ofthe small-di meter piston and low-pressure air acting .against thepiston in the large-diameter piston-cylinder Yon the l down-stroke ofthe plunger, or-liveL air can be admitted to `both pistons on thedownstroke, in. which latter case the saving of volume of air. consumedis -not as great as when the hammer is used on the compound principle,but greater-power of blow is attained. y

When operating the hammer in the firstmentioned manner, employing thelow-pressure motive fluid from the air-receiver to act downward againstthe large-dlameter p piston, the motive fluid is admitted through theinlet passage and, the valve in the first valve-chamber 374 being in'its upper position, will iow between the two large-diametervalve-pistons into the upper end of the small-diameter or high-pressure`cylinder through the passage 46,' forcing the plunger downward todeliver'its blow on the working tool.A Whatever a'ir is in the lowerportion of the large diameter or low-pressure cylinder is forced out bythe large piston, through' the l,passage 85 to the port 84 in thelarge-diameter bore'of the valve-chamber 38 or low-` pressurevalve-chamber, whence it exhausts through. the exhaust-port 82 connectedto said port 84 by the large pistons of the lowpressure valve lwhich isalso in its upper position. When the small-diameter piston in its.down-stroke uncovers the port 50 in its cylinder, the live-air 'passesthrough said 4port and its passage to the upper end of the high-pressurevalve-chamber and forces -down to the position shown infFig. 3, cut-Iting` 0H the live-air supply above the piston. The small-diameterpiston, having gone down to the extreme of its down-stroke, hasuncovered the port 62 and the expanding live-air passes through saidport, through the passage 63 to the small-diameter borepf the hih-pressure valve-chamber,.where the smalliameter valve-pistons 43 and44, be-

ing now in their down positions, connect the port 62 and passage 63 withthe port 55 of` the passage 57, and conduct the expanding air to thereceiver 56. V As the plunger is in its down-position, theupper annulardispassage 85,]carrying the expanding air from the small-diameterpistoncylinder to the lower end of thelarge-diameter piston cylinder where,acting against the large-diameter piston-area 32, it forces the plungerupward. While the plunger is in its down-position, the expanding airwill also pass through the uncovered port 62, passage 63, ports 59 and55 and passage 57 tothe air-receiver. the plunger ascends bythedifferential action vot the expanding air, the air above the largediameter piston passes out through the passage 94 to thevport 93 in thesmalldiameterv bore of the low-pressure valvechamber and, thesmall-diameter valve-pistons connecting said portI with the exhaust port95 and exhaust-passage 96, the air will exhaust to the atmosphere. IWhenthe plunger arrives on its up-stroke to the point where the lowerannular distributing-port 35 in the small-diameter piston connects theports 77 and 80 from the upper ends of the two-valve-chambers with the.lexhaust-port 78, the air above the valves in'such chambers is exhausted,and the live-air which is constantly admitted through the restrictedports 51 and 91 in the valve-chambers will exert differential pressureagainst the larger and smaller areaslof the two middle pistons of eachof the valves and, the pressure against the larger pistons prevailing,will move both of said valves upward, again repeating i the operation.As now the low-pressure or partly expanded a1r is stored in thereceiver,

. such air passes through the passage 57, ports 55 and' 53; and passage54, hich are connected by the small-diameter valve-pistons "435'and 44in their upper positions, as in Fig.

2,' i nto the upper end of the large-diameter piston-cylinder, wardat-th'e same time live-air acts in the upper end of the small-diameterpiston- Jlsively. After the high-pressure air has cylinder and drivesthe plunger down by direct pressure. The air below the largediameterpiston freely exhausts through the passage 85 vand ports 84 and 82 inthe upper portion of the low-pressure valvechamber 38, tothe-atmosphere, admitting of the plunger delivering an unobstructedblow.

From the above it will appearthat highpressure air and low-pressure airsimultaneously coperate to augment the operative down-stroke of theplunger, that low-pressure air, only, is employed -to return theplunger, andthat the valves are actuated in one direction bylow-pressure air and in the opposite direction by constant live-airpressure without exhaust, and that the'only exhaust is of low-pressureair which has performed its functions, directly and expanforced thepiston'down to deliver theblow, a part of the expanding air is directlyemployed to return the piston and a part is stored away in the receiverto be employed to a'ct against the low-pressure piston of the plunger inthe drivin stroke of the latter andto actuate the alves. No air isexhausted excepting the low-pressure air which has been used in thelow-pressure cyl- -inder and in the valve-chamber, so that higheiiiciency is attained by using the air at its original pressure andthereupon again by compound use of the expanded low-pressure airexhausted from the high-pressure cyllnder.v v Y When itis desired toemploy live-air d1- rectly to drive the plunger downward by acting onbothv the small and large diameter pistons, the valve plug 61 in thelive-air in this case contains live-air Aat the working' 5o' duct 60isopened and the plug 64 inthe du'ct .63 is closed, so that when thelive-air valve in the chamber 37 is down, live-air will pass through thepassage 60, ports 59 and 55and passage 57 to the receiver whichpressure. When the valve'isshifted into its upper position7 the live-airis directly admitted to the small-diameter plunger-piston and fromthereceiver to the large-diameter piston, so that the actuating stroke ismade with live-air on both pistons. The operation of the toolA isotherwise the same as that-'above' described, excepting that therefceiverjcontains live-air instead of partly expanded air.

vBy making the tool with grooves in the cylinder jacket ,and in thebarrel-block and covering such grooves by the lining sleevev and byfitting the groovedbarrel-block in the jacket, and thus forming thelongitudinal passages, all drilling of such passages will vbe avoidedwith the expense and time driving the plunger -downthe double required,as the grooves and channels can .be cut in less time and at less expensethan the passages can be drilled. Plugging of the ends of such drilledpassages with the expense and time'involved is also avoided. The jacketor casing can be made froml milder and less expensive metal than a solidbarrel with drilled channels, and the liningsleeve and barrel-block,only, need be of hard and wear resisting metal.` In assembling the tool,the tool-socket and the recoilabsorbing sleeve is rst placed in thejacket from the upper end of the latter, the liningsleeve is theninserted, whereupon the plunger is placed with its piston in the bore 30of the barrel-block and said elements inserted and locked in place bythe handle- ,suchpart or parts may be removed and replaced witho-utcompletely removing and replacing an entire barrel, for instance,whereby considerable expense 'of repairs v can be avoided.

As the working plunger is returned by the expanded live-air actingagainst differential piston-areas, theback-stroke or up-st'roke of suchplunger is cushioned, and shock of the tool from recoil reduced, easingthe hold of the tool to the work.

' By providing the constant live-air cushion 100 for absorbing therecoil of the tool, the tool will work with a minimum ofy recoilnotwithstanding the great power imparted by action of the motive fluidacting i against two pistons. 105

For ordinary work the hammer can be operated by' partly normal-pressurelive-air and partly air expanded after directaction, and a large savingof the volume of air consumed canA bev attained, and whenever by simplyturning the' two valve-plugs. The 115 same tool can thus be employed forlight work, such as chipping and cal'king and vfor light riveting, andbe adjusted to heavy work, such as heavy riveting, whereby the cost ofinstallation of tools in a shop or yard can bev considerablyreduced'from the cost of installing separate light and heavy tools.Owing to the construction of the tool with the -motive fluid. actingupon differential areapistons, the tool can be made comparatively shortin proportion to its power. In either formv the live-air acting againstthe small-diameter plunger-piston is not exhausted, but is used toactuate the plunger in its'up-stroke, and in the seco'ndkdisclosed 130form of operating the hammer, the expanded air from the back of thelarge-diameter plunger-piston, only, is 'directly exhausted, -so' thateconomy of volumel of air when the tool is operated with double directaction, is partly attained:

While my present invention is particularly adapted to smaller or mediumplunger having differential area pistons and 70 sized pneumatic hammerswhich are adapted to l'be .manually held in the hand of the user, it 'isobvious that the broad prin- ;ciples of the same may be employed in laI' el tools or implements or in other fluid (Ilstribution systems4wherein it may orimay not be desirable to employ 1n the same structureveither the compound principle, or, .in other Words, live air actingagainst the face of the small diameter piston, and low pressure airacting against the piston in the large dialneter piston cylinder on thedownward 0r be admitted to both pistons on the downward or outer strokeAupon the proper manipulation or adjustment of the valve mechanism.

It will also be apparent that Awhile I have shown my invention'asapplicable to` that type of pneumatic hammer wherein the forward end ofthe barrel, cylinder jacket, casmg or piston cylinder is open for thereception of the shank of the working tool, and

wherein a grasping handle is employed to hold the tool up to its work,said invention Iis equally' applicable to other types of tool and totools wherein said grasping handle may be dispensed with, and the toolheld up to its work by mechanical devices or the like.

Other modes of applying the principle of my invention may be employedfor the mode herein explained. Change may'therefore be made as regardsthe mechanism thus disclosed, provided the principles oi? construcouterstroke of the plunger, or live air cantion set forth, respectively, inthe following enable live-air to be admitted at will to said plunger. v

' 2. In a pneumatic impact tool, a pistonl cylinder having differentialpiston chamfbers, a plunger havingdiferential area pistons,a,vvalve-mechanism, a receiver, means for operating said plunger andvalve mechanism by the pressure of expanded air in said receiver, meansfor cutting oil' expanded airA and admitting live air to said receiver,and

means for enabling live air to be simultaneously admitted at will tosaid pistons.

3. In a pneumatic hammer, a piston cylinder having differential pistonchambers, a

slida le in said chambers, means for simultaneously admitting livemotive fluid to said pistons, and means for controlling the passage oflive air or expanded air tothe large diameter piston chamber. v

4. In a pneumatic hammer, a pistoncylinder having differential pistonchambers, said cylinder having its forward end .open for theinsertion ofthel shank of the working tool, a plunger having differential area scpistons slidable 1n said chambers, means for simultaneously admittinglive motive fluid to said pistons to impel the' latter towardsaidworking tool, and means for controlling the passage of live air orexpanded air to the 35 large diameter piston chamber. 5. In a pneumatichammer, a piston cylinder having a large diameter and a small diameterpiston chamber, a plunger having a large diameter and a small diameterpiston respectively reciprocal' in said piston chambers, means foradmitting live motive lluid to the corresponding faces of said pistons,and means for controlling the passage of live air or expanded air to thelarge dlameter iston chamber. j

6. n a pneumatic impact tool, a piston cylinder having differentialpiston chambers, a receive, a plunger-having differential area pistonsslidable in said chambers, conv nections from said receiver to saidchambers, means for simultaneously admitting live motive fluid to oneside of each of Said pistons, andmeans for conveying expanding motivefluid from thev small diameter v)L05 piston chamber to the opposite faceof the piston in the large-diameter chamber.

7'. In a pneumatic hammer, riveter. or chipper, a small diameterpiston-cylinder, a

large diameter piston-cylinder, a plunger having a small 4and. a largediameter piston respectively reciprocable in said cylinders, means forsimultaneously admitting livenmotive fluid into the upper ends of saidcylinders, means -for intermittently connecting y the small-d1ameterpiston-cylinder with the large-diameter piston-cylinder to enable themotiveuid to act differentially upon thev faces of said pistons, andmeans for controlling the admission-.of live air or expanded air fromsaid small` diameter piston `ghamjber to said large diameter pistonchamer. 4

8. In a Ipneumatic impact tool, a pistoncylinder having dilerentialpiston chambers, a plungerhaving diierential area pis- Y s tons slidablesaid chambers; means for simultaneously admitting live` motive Huid toone side ofA each of said pistons, aV receiver having controlled' meansfor connecting it 130 l y small diameter admission.

to receive expanded air from the small diameter piston-chamber, andmeans for connecting said receiver and the largediameter piston-chamber.

9. In a pneumatic impact tool, a pistoncylinder having differentialpiston-chambers, a plunger having differential area pistons slidable insaid chambers, and means for controlling the admission of live-air orexpanded air from the small-diametei1 piston-chamber to thelarge-diameter piston chamber.

10. In a pneumatic impact tool, a pistoncylinder having differentialpiston-chambers, a plunger having differential area plistons sflidablein said chalnbers, a receiver, means for controllably connecting saidreceiver to live motive-fluid supply `or to the small-diameterpiston-chamber to receive expanded motive fluid therefrom, and means forintermittently admitting motive fluid from said receiver to thelarge-diameter piston-chamber.

1l. In a pneumatic hammer, riveter or chipper, la series of cylinders ofdierent diameters, pistons of different diameters in said cylinders,means for utilizing the energy left in the expanded air after it hasbeen used,.means for controlling said means, means' for admitting livemotive fluid to said cylinders, means for controlling the supply ofmotive fluid to such admissionmeans, and means for l controlling the adimission of live air or expanded air from the diameter piston chamber.

a small-diameter and a large-diameter cylinder portion, a plunger havinga small-diameter and a large-diameter piston respectively reciprocablein said cylinder-portions, areceiver, a high pressure inlet controllingvalve, said small-diameter cylinder-portion having a passage near itslower end connected at intervals to said receiver by said valve, meansfor controlling said passage, means for admitting live motive fluid tosaid receiver, and means for controlling such 13. In a compoundpneumatic impact tool, a plurality of Working cylinder-portions ofdifferent diameters, a Working plunger havy ing pistons of differentdiameters reciprocable in said cylinder-portions, means for admittingmotive-fluid to a small-diameter cylinder-portion, a receive, means foradmitting expanded motive-fluid from said small-diametercylinder-portion to such receiver, means for controlling such admittingmeans, means for admitting live motive fluid to said receiver, means forcontrolling said latter means, tive-fluid from sald recelver to alargediameter piston.

14. In a pneumatic impact tool', a pistonpiston chamber to the large thegrooves,

and means for admitting mocylinder having differential piston-chambers,a plunger having differential area pistons slidable in said chambers,vmeans for controllably admitting live air or expanded diameter and asmall diameter piston-chamber, a plunger having a large-diameter and .asmall diameter piston respectively reciprocable in said piston-chambers,means for simultaneously admitting live motive fluid to thecorresponding faces of said pisfluid from the small-diameterpiston-chamber to the lower end of the large-diameter piston chamber,and means for controlling the admission of live air or expanded air fromt-he small diameter piston chamber to the large diameter piston chamber.

16. In a pneumatic impact tool, a cylindrical casing having an axialbore, a tubular member fitted in said bore and having its bore forming apiston-chamber, the littin surface of said member being formed with alongitudinal groove closed on one side by the surface of the othermember to form a longitudinal passage, and means for enabling saidgroove to serve as a receiver for a compound pneumatic tool.

17. In a pneumatic impact tool, a cylindrical casing having an axialbore, a tubular member fitted in said bore and having its bore forming apiston-chamber, the fitting surfaces of said member and casingrespectively having longitudinal grooves and covering said grooves toform longitudinal passages, and means for enabling certain of saidgrooves to serve as the receiver of a compound pneumatic tool.

18. In a pneumatic impact tool, a cylin drical casing formed withaxially alined bores and with grooves in said \bores, a lining-sleevefitted in one bore to form a piston-chamber and closing the sides of thegrooves in said bore to form passages, and a tubular member fitted inanother bore and having an axial bore forming' a pistonchamber and arecess in its exterior surface forming, together` with the surroundingbore of the jacket, a receiver, and together with passages in theassembled structure.

19. In a pneumatic impact tool, a cylindrical casing formed with axiallyalined bores and longitudinal grooves in said bores,

a lining sleeve in one of said bores and forming a piston-chamber, and abarrel-block fitted in a bore and having its axial bore l tons, 'meansfor intermittently connecting forming a piston-chamber and havinglongitudinal recesses and grooves in its side form ing a receiver andpassages.

20. In a pneumatic impaottool, a\cylin drical casing formed with axiallyalined bores and with grooves in said bores, a lining-sleeve tted in onebore to form a piston-chamber and closing the sides of the grooves inysaid 'bore to form passages, a tubular member fitted in another borehaving an axial bore forming a piston-chamber and a recess in itsexterior surface forming, together with the `surrounding bore of thejacket, a receiver, and together with the grooves, passages in theassembled structure, and a handle-socket secured to said` casing to bearagainstI the end of said tubular member.

. 21. In a ypneumatic impact tool, a cylindrical casing formed withaxially alined bores and longitudinal groovesin said bores,

a lining sleeve in one of said bores and forming a piston-chamber, abarrelblock ao y chipper, a piston-cylinder having differenitted in abore and having its axial bore forming a piston-chamber and havinglongitudinal recesses and grooves in its side forming a receiver andpassages, and a handlesocket s'ecured to said casing to bear'againstthe' end 'of said barrel-block.

22. In a pneumatic hammer, riveter or tial piston-chambers, a plungerhaving differential area pistons slida-ble in said chambers, means foradmitting live motive uid to one of said piston-chambers, means forsimultaneously admitting live motive fluid to the corresponding end ofthe other pistonchamber, means for controlling the live iuid supply tosuch admitting means, means for cylinder-portion, a receiver, means foradmitting expanded iuid from said smalldiameter cylinder-portion to saidreceiver, means connected to coperate with the motive fluid admittingmeans to simultaneously'admit expanded. fluid from said receiver back ofthe large-d-iameter piston, meansYfor controlling such admitting means,and controlled means for admitting motive fluid to said receiver. v

i24. In a compound pneumatlc hammer, a cylinder having a differentialpiston chamber forming high pressure and low pressure vinto saidIsmall-diameter cylinder-portion,

"tion, a plungerhaving` a small-diameter and y receiver, means forcontrolling said passage,

I controlled means for admitting live motive vfluid to said rece1ver,and means coperatcylinders, a plunger therein having high pressure andlow pressure piston areas, a receiver,' a high pressure inletcontrolling valve mechanism, means controlled by the latter forsimultaneously utilizing live motive fluid on the high pressure area ofsaid plunger and expanded motive fluid from said `receiver upon a largerarea of said plunger to drive said plunger downwardly, means forcontrolling the expanded motivefluid controlling means, and controlledmeans for admitting live motive iuid to said large area of the plunger.

25. In a'compound pneumatic impact tool, a small-diameter and alarge-diameter cylinder-portion, a plunger having a small diameter and alarge-diameter piston respectively reciprocable in saidcylinder-portions, means for intermittently admitting motive-Huid' n areceiver, controlled means for conduct- .p ing expanded i'luid fromsaid, cylinderportion to said receiver, controlled means for admittinglive motive-fluid to said re-l ceiver, means connected to themotive-Huid admitting -means to simultaneously 4admit fluid from thereceiver to the large-diameter cylinder-portion back of the piston inthe same, and means for connecting the opposite ends of thecylinder-portions to admit of expanded Huid differentially actingagainst thepistons.

426.v In a pneumatic impact tool, a small-` diameter and alarge-diameter cylinder-pora large-diameter piston respectivelyreciprocable in said cylinder-portions, a ,retceiver, a passage fromnear/the lower end of said small-diameter cylinder-portion to said meansfor yintermittently admittingmotiveiuid to the small-diametercylinder-portion, a passage lfrom said receiver to the upper end of thelarge-diameter cylinder-portion,

ing with suchlmotive liuid admitting means and controlling admission'offluid from said' receiverthrough said passage to said cylinder-portion.Y

- 27. In a pneumatic impact tool, a -smalldiameter and alarge-diameter,cylinder-portion, a plunger' having a small-diameter anda large-diameter piston respectively reciprocable in saidcylinder-portions, means for .120 intermittently admitting motive fluidinto said small-diameter,cylinder-portion, a receiver, a passage fromnear the end of said small-diameter cylinder-portion to said receiver,controlled means for opening and 12.5`

closing such passage, controlled means forl admitting live motive -fluidinto said receiver, a passage connecting ,said receiver and the upperend of the large-diameter cylinder-portion, means for controlling saidpas- 130 sage, `an exhaust-passage from said upper end of saidcyl1nder-port1on, means for controlr ling said exhaust-passage, apassage connecting opposite ends .of the cylinder-portions, and meansfor controlling such passage.

28. In a pneumatic hammer, a cylinder having its forward end open forthe shank of the working tool and provided with a differential pistonchamber, whereby high pressure and low pressure cylinders are formed, areceiver adapted to receive the exhaust from the high pressure cylinderand retain it for use when required in the 10W pressure cylinder,controlled means for opening and closing admittance of such exhaust,controlled means for admitting live motive fluid to said receiver, ahigh pressure inlet controlling valve, and a low pressure exhaustcontrolling valve.

29. In a pneumatic hammer, a handle portion having an extension thereonand provided with a high pressure piston chamber, a cylinder memberdetachably secured to said extension and provided with a low pressurepiston chamber, a high pressure inlet controlling and a low pressureexhaust controlling valve in said extension, a receiver also carried bysaid extension, controlled means for connecting said receiver to theexhaust of the high-pressure piston chamber or the live motive-fluidsupply, and a differential piston in said piston chambers controlled bysaid valves.

30. In a pneumatic hammer, a cylinder member open-at its forward end toreceive the shank of the working tool and bored to form a low pressurecylinder, a handle mem-v ber having an extension thereon with a boretherein of less diameter forming the high pressure cylinder, whereby adifferential piston chamber is formed, means for coupling said cylindermember and handle member together, a differential hammering plungerhaving piston areas of di'erent diameters reciprocating in said lowpressure cylinder and said high pressure cylinder respectively, a highpressure inlet controlling valve contained in the extension of saidhandle member, a low pressure exhaust controlling valve also containedin said extension, a receiver also contained in said extension,controlled means for admitting exhausted motive fluid from the smalldiameter cylinder or live motive fluid into said receiver, and ports andpassages common to 4said valves, receiver and the differential pistonchamber.

31. In a pneumatic hammer, a cylinder having its forward end open forthe shank of the working tool and provided with a differential pistonchamber, whereby high pressure and low pressure cylinders are formed, areceiver adapted to receive the exhaust from the high pressure cylinderand retain it for use when required in a low pressure 'live air teilcylinder, controlled means for opening and closing admittance of suchexhaust, controlled means for admitting live motive fluid to saidreceiver, a high pressure inlet controlling valve, a low pressureexhaust controlling valve, ports and passages common to said valves,receiver and piston chamber, and means for causing live air pressure tbconstantly act upon a portion of each of said valves to shift the same.

32. A pneumatic hammer, comprising a p-iston-cylinder havingvdifferential pistonchambers, a plunger having differential-area pistonsand slidable in said chambers, means for simultaneously admitting livemotive fluid behind said pistons, means for individually controllingadmission of live motive fluid behind the large-diameter piston, meansfor admitting expanded motive fluid from the small diameter cylinder tothe large-diameter pistoncylinder behind the piston in the same, andmeans for individually controlling such expanded fluid.

33 In a pneumatic imp-act tool, a piston cylinder having differentialpiston chambers, a plunger therein having dierential area pistons, andmeans for controlling the ladmission of live air or expanded air fromthe small diameter piston chamber to the large diameter piston chamber,said piston cylinder having its forward end cpen for the1 reception ofthe shank of the working too.,

34. In a pneumatic impact tool, a p-iston cylinder having its forwardend open for the reception of the shank of the working tool and providedwith differential piston v,chambers, a plunger'therein having'4differential area pistons, means for controlling the admission of liveair or expanded air from the small diameter piston chamber to the largediameter piston chamber, and a grasping handle secured to the rear endof said cyl'- inder.

35. In a pneumatic impact tool, a piston cylinder having differentialpiston chambers, a plunger therein having differential area pistons, areceiver, and means for controlling the passage of live air or expandedair from said receiver-to the large diameter piston chamber.

36. In a pneumatic impact tool, a piston cylinder having differentialpiston chambers, a plunger therein having differential area pistons, areceiver in said piston cylinder, and means for controlling the passageof or expanded air from said receiver to the large diameter pistonchamber.

37. In a pneumatic impact tool, a piston cylinder having its forward endopen for the reception of the shank of the working tool and providedwith differential piston chambers, a plunger thereon having differentialarea pistons, 4a receiver located within said piston cylinder, and meansfor controlling the passage of live air or expanded air from saidreceiver to the large diameter piston chamber.

38. In a pneumatic impact tool, a piston cylinder having differentialpiston chambers, aplunger in said cylinder having differential pistons,means for enabling either live motive fluid or expanded motive fluid tobe simultaneously admitted to one side of said pistons, and meansforcontrolling the exhaust from said pistons.

39. In a pneumatic impact tool, a piston cylinder, a plunger in saidcylinder having differential pistons, valve controlled means forenabling live motive fluid to be simultaneously admitted to one side orboth of said pistons, and other valve controlled connections forenabling live mot-ive fluid and expanded low pressure fluid-to beadmitted at will to said side of said pistons.

40. In a pneumaticl impact tool, a piston cylinder having differentialpiston chambers, a plunger in said cylinder having differential pistons,a receiver, and means for enabling either live motive fluid or exp-andedmotive fluid to be admitted through the medium of said receiver to oneside of said pistons to drive said plunger outwardly.

41. In a pneumatic impact tool, a piston cylinder having its forward endopen to receive the shank of the working tool, differential areapistons, a receiver in said cylinder, and means for controlling theadmission of live air or expanded air from said receiver to the lowpressure piston chamber.

42. In a pneumatic impact tool, a piston cylinder having its forward endopen to receive the shank of the Working tool, high pressure and lowpressure chambers in said cylinder, a plunger therein having pistons ofIdifferent areas, controlling. means for permitting the admission of l1veair or expanded air from said receiver to the low pressure piston, and agrasping handle attached to'said cylinder and having a manuallycontrolled pressure supply duct therein.

43. In a pneumatic impact tool, a piston cylinder, high and low pressurechambers therein, a plunger having pistons of different areas, areceiver formed in the body of said cylinder, and controlling means forpermitting the admission of live air or expanded air from said receiverto said low pressure chamber.

44. In a pneumatic impact tool, a cylinder, a piston therein, a valvemechanism, a receiver formed in said cylinder, and means for operatingsaid piston and valve mecha-- nism by the medium of the pressure of themotive fluid passing through said receiver.

45. In a pneumatic impact tool, a piston cylinder having differentialpiston chambers, a plunger having differential area pistons slidable insaid chambers, a receiver, and means for `controllably connect-ing saidreceiver to live fluid supply or connecting it to the small diameterpiston chamber to receive expanded motive fluid therefrom.v

46. In a pneumatic tool, the combination of a piston cylinder, a plungertherein having small and large diameter pistons, a valve mechanismtherefor, a receiver, means for enabling live mot-ive fluid to entersaid receiver and act directly upon both said small and large diameterpistons to augment the striking blow of said plunger, and meansforenabling the used motive fluid to exhaust to the atmosphere.

4". In a pneumatic tool, the combination of a piston cylinder, a plungertherein having small and large diameter pistons, a valve mechanismtherefor, aV receiver, and means for enabling said receiver to be filledwith either live motive fluid or expanded motive fluid at Will.

48. In a. pneumatic tool, the combination of a piston cylinder. aplunger therein having small and large diameter pistons. a valvemechanism therefor, a receiver, means for enabling said receiver to befilled ivith either. live motive fluid 0r expanded motive fluid at will,in combination with means for effecting the exhaust. of the expandedmotive fluid.

49. In a pneumatic impact tool, a cylinder, a hammering plungertherein,avalve mechanism, a receiver, and means for operating saidplunger by motive fluid through a passage or chamber which isuninterruptedly in communication with the receiver and forming a partthereof.

50. In combination with a pneumatic impact tool, a receiver, and meansfor cushioning the recoil of the hammering plunger by live motive. fluidfrom a passage or chamber which is constantly in communication ivithboth to the receiver, and means for operating said plunger by motivefluid passing through said receiver.

53. In a pneumatic impact. tool, a plunger therein, a valve mechanism, areceiver, and

means for admitting' live or expanded air or both to the receiver, andmeans for operating said valve mechanism in onel direction by motivefluid passing through said receiver.

54. In a pneumatic impact tool. a plunger therein. a valve mechanism, areceiver, means for operating said plunger by motive fluid passingthrough said receiver, and means for operating said valve mechanism in onedirection by motive Huid which does not pass through the receiver.

55. A combination of a pneumatic impact tool, a receiver, a valvemechanism and means for cushioning the recoil of the in serted tool bylive motive Huid supplied from ya passage or chamber which is constantlyin communication and forms a part of the receiver.

56. A pneumatic impact tool, a plunger therein, a valve mechanism, areceiver and means for admitting live air to the receiver and means foroperating said valve bv live motive fluidy from a passage or chamberwhich is uninterruptedly incommunication with the receiver` and forms apart thereof.

57. In a pneumatic impact tool, a plunger therein, a valve mechanism, areceiver, and

.means for operating the said valve and plunger by live motive fluidfrom a chamber -or passage in constant communication With the receiverand forming a part thereof.

58. In a. pneumatic impact tool, a receiver,

and means for absorbing the recoil of the inserted tool by pneumaticpressure supplied through a passage or cham'ber in uninterruptedcommunication With the receiver and forming a part thereof.

59. In a pneumatic impact tool, a receiver, and means for absorbing therecoil of the inserted tool by a constant pneumatic pressure suppliedthrough a passage or chamber in uninterrupted communication With thereceiver and forming a part thereof.

60. In combination with a pneumatic impact tool, a receiver and passageor chambers connected therewith and forming a part thereof,'and apneumatic shock absorber coacting therewith between the inserted tooland the barrel.

61. In a pneumatic impact tool, a cylinder, a plunger therein, a valvemechanism9 a receiver which is constantly in'communication with livemotive fluid, and means for operating said plunger and valve mechanismby a medium of the pressure of the motive Huid supplied from a passageor chamber in uninterrupted. communication with the receiver and forminga part thereof.

62. In a pneumatic impact tool, a cylinder, a valve mechanism, areceiver and chambers or passages in constant communication therewithand forming a part thereof, through which live motive fluid passes, anda plunger With two or more diameters to receive the working fluidpressure on its striking stroke.

63. In a pneumatic impact tool, a cylinder, a plunger, a valvemechanism, a receiver and chambers and passages connected therewith anda part thereof, through Which the motive fluid passes for operation ofthe various reciprocatory parts.

64. In a pneumatic impact tool, a cylinder, a plunger, a valvemechanism, a receiver and passages and chambers connected therewith and`a part thereof from which is derived pneumatic pressure to form an aircushion for preventing the Contact of the end of the plunger on itsrecoil stroke With the end of thepcylinder.

65. In combination With a pneumatic tool, a receiver and means foradmitting live or expanded air thereto at will.

66. In a pneumatic impact tool, the combination of a cylinder, aplunger, a valve mechanism, a receiver, and means for introducing intothe receiver live or expanded air at will.

67. In a pneumatic impact tool, the combination of a cylinder, a plungertherein, a receiver, and means for enabling live or expanded motive Huidto enter therein at Will.

68. In a pneumatic impact tool, the combination of a cylinder, aplunger, a valve mechanism therefor, a receiver, and means for enablinglive motive fluid to enter therein.

WILLIAM BURLINGHAM.

Witnesses:

H. S. FAIRBA-Nxs, C. D. MCVAY.

